Recent trends in telecommunications equipment and computer systems, in particular, employ an open architecture, modular approach in their design in order to accommodate sharing of resources and system expansion as well as physical distribution over potentially wide areas. This trend has necessitated use of distributed power systems. For example, widespread use of the Internet requires infrastructure support to provide a high-quality and reliable power network that must necessarily be distributed. On a much smaller scale, increased functionality of data processors fabricated at increased integration density is requiring lower voltages and higher currents such that high quality power with accurate voltage regulation often must be provided at the point-of-load (POL); requiring numerous power converters in a single device or even a plurality of power converters for a single chip.
It is therefore foreseeable that future electrical power processing will have virtually all electrical loads interface to energy sources through power electronics circuits or devices. Advanced power processing systems will be expected to achieve fully controllable, fully reconfigurable, autonomous platforms that can be customized for electrical energy supply in such applications as telecommunications, computers, Internet infrastructure, automotive and aerospace applications and the like and will be required to provide on-demand power from respective available sources to loads at any rate and in any desired form.
To support these trends, greater numbers of advanced power processors have been employed in many diverse devices together with customized and miniaturized power POL converters which must also be reduced in size as much as possible. High power density (e.g. Watts per unit volume) and high efficiency are major objectives for power (e.g. DC/DC) converters but success in simultaneously achieving such objectives is often limited by various trade-offs. For example, to increase power density, high switching frequency can increase the control bandwidth so that fewer and/or smaller capacitors are needed to meet transient requirements but such high frequency switching may cause high losses in switching, drivers and body diodes of synchronous rectifiers (SRs). Due to such trade-offs, current approaches to power converter design and known power converter topologies are inadequate to meet foreseeable requirements of power density and efficiency.